Refactor trap handling to support task gates

xtoskrnl/ar/i686/archsup.S

@@ -4,6 +4,7 @@
  * FILE:            xtoskrnl/ar/i686/archsup.S
  * DESCRIPTION:     Provides i686 architecture features not implementable in C.
  * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ *                  Aiken Harris <harraiken91@gmail.com>
  */
 
 #include <ar/i686/asmsup.h>
@@ -13,22 +14,49 @@
 
 
 /**
- * Creates a trap or interrupt handler for the specified vector.
+ * Creates a task, trap or interrupt handler for the specified vector.
  *
  * @param Vector
- *        Supplies a trap/interrupt vector number.
+ *        Supplies a vector number.
  *
  * @param Type
- *        Specifies whether the handler is designed to handle an interrupt or a trap.
+ *        Specifies whether the handler is designed to handle an interrupt, a task or a trap.
  *
  * @return This macro does not return any value.
  *
  * @since XT 1.0
  */
-.macro ArCreateTrapHandler Vector Type
+.macro ArCreateHandler Vector Type
 .global _Ar\Type\Vector
 _Ar\Type\Vector:
      /* Check handler type */
+    .ifc \Type,Task
+_Ar\Type\Vector\()Start:
+        /* Clear the Task Switch flag */
+        clts
+
+        /* Allocate the trap frame and inject the hardware vector for the dispatcher */
+        sub $TRAP_FRAME_SIZE, %esp
+        movl $\Vector, TrapVector(%esp)
+
+        /* Pass the trap frame pointer as an argument and clear the direction flag */
+        push %esp
+        cld
+
+        /* Pass control to the trap dispatcher */
+        call _ArDispatchTrap
+
+        /* Discard the argument and deallocate the trap frame */
+        add $4, %esp
+        add $TRAP_FRAME_SIZE, %esp
+
+        /* Hardware task return */
+        iretl
+
+        /* Spin back to the entry point to rearm the task gate */
+        jmp _Ar\Type\Vector\()Start
+    .else
+        /* Check handler type */
         .ifc \Type,Trap
             /* Push fake error code for non-error vector traps */
             .if \Vector != 8 && \Vector != 10 && \Vector != 11 && \Vector != 12 && \Vector != 13 && \Vector != 14 && \Vector != 17 && \Vector != 30
@@ -141,13 +169,18 @@ KernelModeReturn\Type\Vector:
         /* Skip error code and vector number, then return */
         add $(2 * 4), %esp
         iretl
+    .endif
 .endm
 
-/* Populate common interrupt and trap handlers */
+/* Populate common interrupt, task and trap handlers */
 .irp i,0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
     .irp j,0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
-        ArCreateTrapHandler 0x\i\j Interrupt
-        ArCreateTrapHandler 0x\i\j Trap
+        ArCreateHandler 0x\i\j Interrupt
+        .if 0x\i\j == 0x02 || 0x\i\j == 0x08
+            ArCreateHandler 0x\i\j Task
+        .else
+            ArCreateHandler 0x\i\j Trap
+        .endif
     .endr
 .endr
 
@@ -165,6 +198,10 @@ _ArInterruptEntry:
 _ArTrapEntry:
 .irp i,0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
     .irp j,0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
+        .if 0x\i\j == 0x02 || 0x\i\j == 0x08
+            .long _ArTask0x\i\j
+        .else
             .long _ArTrap0x\i\j
+        .endif
     .endr
 .endr

xtoskrnl/ar/i686/traps.cc

@@ -195,7 +195,6 @@ VOID
 AR::Traps::HandleTrap02(IN PKTRAP_FRAME TrapFrame)
 {
     DebugPrint(L"Handled Non-Maskable-Interrupt (0x02)!\n");
-    KE::Crash::Panic(0x02);
 }
 
 /**